I've noticed this little (harmless) exploit and decided to test it further. Apparently this interesting exploit of game mechanics is harmless and won't get you banned. Anyway, both factions have access to this, however its harder for the Horde since it involves going into Wetlands and is generally out of the way for Horde. This screenshot here shows where it is. There's only two types of mobs, not counting the special-named questmobs. Cursed Sailors, and Cursed Marines. Both mobs are relatively harmless and both can cast an ability called "Curse of the Eye" which turns the target into an Undead Male or Female. At first I thought it was random when it happened to my pet, but found it to repeat itself. Oddly, I found my Voidwalker is a female, my Imp a male, and my Succubus a female (was hoping for a Transexual for lulz). It seems these effects do not change from logging off and back in.
Higher level's will have a harder time since Pet's have resist checks like anything else. But either way, if you get your pet turned into an Undead Male or Female, congrats! You now know what the gender of your pet is. A cool trick is to dismiss your pet, then go into a major city, or PvP, and call it back and sick it on the Alliance or Horde. Lulz are to be had.
http://i90.photobucket.com/albums/k2...008_160047.jpg Oddly, I find it funny I'm commanding an Undead female.
http://i90.photobucket.com/albums/k2...008_160812.jpg
More fun.
http://i90.photobucket.com/albums/k2...008_162336.jpg
My new Undead pet using 'Consume Shadows'.
http://i90.photobucket.com/albums/k2...108_203602.jpg
Apparently my Imp is Male.
http://i90.photobucket.com/albums/k2...108_203720.jpg
And that my Succubus is Female.
http://i90.photobucket.com/albums/k2...108_204034.jpg
A map of the location of where these mobs are located.
Creature: Cursed Sailor
Creature: Cursed Marine
Mob info.
Curse of the Eye
Actual spell info.